Brazoria County, TX

ZIP 77566

In ZIP 77566, 7 of the 12 things we check have at least one part graded D or F.

• Drinking water: Key Largo Utilities meets every EPA legal limit; 3 contaminants are above health goals, led by arsenic at 800× California’s Public Health Goal.
• Nearest Superfund site: Gulfco Marine Maintenance, 3.5 miles away.
• Largest share of modeled toxic air from industry: Dow Chemical Co Freeport Facility (64%), mostly ethylene oxide.
• Fine particles (PM2.5) average 7.3 µg/m³; the WHO guideline is 5 and the EPA annual standard is 9.
• About 126,183 kg of agricultural pesticides are applied in the county each year.

Grades for ZIP 77566

• Superfund sites nearbyA to F
• Factories and industrial sitesF
• Oil and gas wellsD
• Parks and nature nearbyB to C
• Air qualityC
• Drinking water qualityB to D
• Pesticide useC to D
• Neighborhood health statusB to F
• Past wildfire impactsA
• Past flood impactsC
• Noise levelsA to D

Based on 10 census tracts · compiled October 25, 2026 · how each grade works and its sources

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